Action is something this 27-year-old explorer and ecologist knows all about. An expert in carnivorous plants, he has travelled to some of the world’s remotest regions in search of hitherto unknown species.

Sitting in the same Hamworthy home where as a child he used to give his astonished parents detailed lectures on the mechanics of the Venus Fly-trap, he talks of the kind of expeditions that to most of us are the stuff of Indiana Jones movies. The time for instance when he was guided up a distant mountain in the Philippines by a trio of machete-wielding murderers. “It was on land used by a penal colony,” he explains. “We had to get special permission. The prison authorities eventually agreed, but insisted we took these guys with us.

“It was an amazing trek and when we finally got to the top - 2000 meters up - we discovered a plant that hadn’t been seen since 1899.”

I ask how he got on with the murderers “Oh they were great fellows, absolutely lovely chaps...and an enormous help clearing our path with their machetes.”

Wasn’t he just a little bit worried? Stewart laughs. “No, not at all. I think they might have had some awkward questions to answer if we hadn’t come back.”

I am talking to Stewart during a trip home visiting his parents, Malcolm and Ann and younger sister Sophie. He only graduated from university four years ago but is already a seasoned explorer and author of eight specialist books published by his own company Redfern Natural History Productions.

He is currently studying Mount Roraima, a huge plateau deep in the Guiana Highlands of Venezuela. Skirted on all sides by towering 600 meter high cliffs, this is just one of a hundred plateaux to be found in this densely impenetrable region.

They have remained isolated for 70 millions years, each developing its own unique ecosystem.

Roraima is particularly spectacular, a place of dark legends and superstitions among the tribespeople who inhabit the ancient jungles that stretch for a thousand miles from its base. They regard it as home of the Gods, the place that takes the souls of disgraced warriors.

It remained untouched by man until the 19th century when an ornithologist stumbled upon an overgrown ledge leading from top to bottom. As attempts were made to make the climb, Victorian scientists began to seriously speculate that Roraima could be home to dinosaurs or even undiscovered human civilisations.

Finally in 1884 an intrepid botanist called Everard Imthurn made the first ascent and described the sights that greeted him as “some strange country of nightmares”.

He spoke of his findings in a celebrated lecture at the Royal Geographic Society. Among those in the audience was Sir Arthur Conan Doyle who stepped out into the streets of London that night with the inspiration for his book The Lost World.

Though Roraima does not actually harbour dinosaurs or indeed lost civilisations, it offers what is perhaps the greatest concentration of unique plant and animal life on our planet.

The arrival of man has done it no favours. Describing it as being like an “island above the clouds” – so physically and ecologically isolated that 70 per cent of its life-forms are found nowhere else on Earth – Stewart says he fears for its future.

Until recently he was among just a handful of experts who had made the arduous journey to this mysterious land on top of the world. He talks of its dramatic valleys and labyrinths of towering, twisted stone, a landscape studded with banks of crystals and carpeted with brilliant red gemstones. Of electric blue plants and massive waterfalls.

However, increasing accessibility is gradually bringing in wealthy tourists and with them the introduction of foreign plants and animals. There are also gangs of illegal gold miners and the temptation for visitors to fill their pockets with handfuls of semi-precious stones.

With alarming speed this unique natural wonder is being seriously degraded.“Last time I was there was a year ago and I counted 25 species of introduced plants that have basically arrived on the shoes of new visitors.” he says.

“There are animals too that have followed trails of food left by humans.” Stewart is appalled by the implications. “The introduction of new species is wreaking havoc and will literally wipe out the ecosystem.”

Now he has joined the environmental charity Ibex Earth in a project that is looking for ten young adults to join an internationally acclaimed team of documentary film-makers on an expedition to discover and film the wildlife, landscapes and highlight the growing threats faced by this extraordinary place.

Sitting alongside his father Malcolm, who helps run the Redfern Natural History Productions publishing business, Stewart told me: “We want to raise awareness of the fragility of this area and the conservation concerns. We’re incredibly lucky with the Ibex Earth Project because we’ve got the lead cameramen from BBC ‘s Planet Earth on board as well as a top BBC producer.”

The resulting 50 minute documentary about the unique wildlife of Roraima will, he hopes, raise the profile of the efforts that need to be made to protect it.

“This is wonderful for me because I desperately want to tell the story of this amazing place and do whatever I can to help. I know we could face criticism because by simply showing the film we will be revealing Roraima to more people.

On the other hand if no one knows what’s happening nothing will ever be done to stop it. I think it’s really important that the damage and destruction is documented and shown.”

Talking to Stewart it is clear that as well as the tens of thousands of geographic miles he has covered, he has also made a long and fascinating personal journey since the days when he used to run the stick-insect club at Castle Court School in Corfe Mullen.

Malcolm tells me that he never doubted his son would end up doing something extraordinary.

“When he was a kid he wasn’t really like other children. I remember he used to love going to Poole Aquarium. He was always there and so fascinated by the wildlife that when one day they got a virus and had to evacuate everything they asked Stewart if he could help.

“We cleared out his bedroom and put them all in there for a while. Walls and walls and walls of snakes, millipedes and snails. The noise was amazing. It was like a zoo. His friends were too frightened to sleep over. I suppose he was about 10 at the time.”

The Lost World Project is a fundraising competition organised by environmental charity Ibex Earth that aims to provide 10 young adults with the adventure of a lifetime. The winners will join an internationally acclaimed crew of professional documentary-makers and travel to Mount Roraima, Venezuela, in August (2010) to help shoot footage for a 50 minute, broadcast-quality documentary.

During the 14-day expedition the team will explore the ‘Lost World’ plateau and film the unique wildlife and haunting scenery that has remained unchanged for millions of years. The overall winner of The Lost World Project, will then remain with the crew for an additional three weeks to undertake final filming sequences and complete the documentary. The Lost World Project will then be premiered in London in December 2010, and across the UK from January 2011. For details of how to enter ‘The Lost World Project’ competition, log on to www.ibexearth.com and follow the links to the Lost World Project.

The man who discovered a rat-eating plant

Stewart McPherson made international headlines last summer when it was revealed that he had discovered a huge but previously unknown variety of pitcher plant growing on the slopes of a distant mountain in the highlands of the Central Philippines. The press had a field day when they learnt that it was big enough to trap small rodents and dissolve them with its flesh-eating enzymes. Stewart instantly became the man who had discovered a rat-eating plant.

He laughs at the idea. “ It’s true plants do on occasions kill rodents. Occasionally rodents fall into the pitcher. I myself have found dead mice in them in Borneo and Philippines but they haven’t evolved to do this, they have evolved to trap and kill insects.”

McPherson went on to name the new plant nepenthes attenboroughii as “an expression of gratitude” to the man he regards as one of his greatest influences, Sir David Attenborough.

Sir David responded by telling the world’s media that he was delighted with the honour and considers the plants to be both “elegant and charming.” Since last summer Stewart has discovered several even larger pitcher plants.